Apparently every open world game setting is an archipelago

Like others have said, you could add a boundary like a mountain region or large, instant-death, canyon to the borders of the map.
And looking at the pre-San Andreas GTA games, you were unable to swim so going in the water would kill your character. Same with the first Jak and Daxter game. Although you could swim, going too far from shore would result in a shark eating you. They also had unscale-able mountain boundaries or large city walls in the Jak series.
This is also in GTA V. The game has a rather massive map in a waterworld, but it lets you swim, fly planes, drive boats, and basically have the power to venture far away from the main map. However, once you reach a certain point in the ocean, your vehicle will spontaneously die, and you'll get eaten by a shark.

Merry Christmas Sir.

I've complained about this as it pertains to GTA a lot. It's really silly. The endless emptiness of the sea makes the islands seem like the only human habitats on Earth. No one in the games even suggests that they're on islands. I'd rather have mountain ranges and "Cannot proceed beyond this point" messages like in Skyrim. Natural maps. If you fly too far into death valley, your plane should automatically be turned around. If you drive too far on a desert road, your car should slow to a stop, forcing you to reverse and turn. They could put signs along the roads warning you of dead ends. "You are leaving San Andreas"

Don't see what the big deal is. I much prefer they surround the cities with bodies of water than have inaccessible landmasses/invisible walls to prevent you from leaving.

Skyrim uses invisible walls and game objects to keep you on the map. In addition to those tricks it also uses the infinite sea tactic. On Skyrim it is quite easy to break through the invisible walls on the top of the map. There's a gate that is relatively easy with some determined jumping to get over. Once you are over the game becomes like ICO, with a vast area with light vegetation (without the awesome boss fights). After that, there is large hills mountains with no vegetation which you can walk on for an extremely long distance before the mesh you are walking on disappears. Then you land in an infinite ocean and can swim to a low-poly tower that disappears when you get near it. I don't quite understand why they put the tower in as when you are in the intended map area you normally you cannot sea over the hills. Perhaps it is for when you ride the dragon?

You can even accidentally ride a horse off the top of the Skyrim map into ico-land.

I remember in one of the original Spyro games there was a hockey match. You could fly from some wall directly across to a specific point on the hill (the hill which was meant to keep you inside the level). You could then move along the hill, around, and then through the roof of the yeti locker-room. The yeti characters would also be inside this room (which you are not meant to see inside of).

@afrofools: I wanna remember that the tower and surrounding areas represent the imperial city and the country you spend time in while playing Oblivion. Potentially for DLC, but most likely just for fun. I wanna say there is a similar thing around where Morrowind should be.

@tobbrobb: Yeah, I think it was volcano. I appreciate developers putting in little things like that.

Skyrim does it well too, the whole continent is there, but with invisible walls that keep you in Skyrim. You can talk up to the top of the mountain and see the land go on and on...I wish the game was better...but the fact remains the land mass is impressive.

I'm currently working on an open-world game that solves this problem myself. Only my open world game takes place in space. Basically, my world is a coordinate system and points of interest/areas are delineated by your current coordinates. My world is as potentially large as numbers can be in the IDE I'm using: which is amazingly freaking huge. Of course, it'll all be pretty crappy if I don't at least populate the world with some interesting things to do which is up next after I get my engine running as best I can.

Why must you remind me that @jay444111 is no more?

Wow, necro thread much?

@mysteriousbob: I enjoyed finding invisible walls in Skyrim/Oblivion. Afterwasting so much time trying to find a way over the border mountains it felt like "winning" when I finally got to the slopes on the other side and hit a "turn back" message.

One solution that is rarely used these days is where the world is just repeating, like in Magic Carpet and 1nsane. I kinda like that solution even though it certainly doesn't look realistic when you come back to spot you started at if you drive west for 15 minutes.

If you're standing in the right area in Skyrim, you can see the Imperial City from Oblivion way off in the distance. It's pretty cool.

Well both time travel and spherical worlds has been achieved on consoles last millenia so welcome to the future. http://www.giantbomb.com/chrono-trigger/3030-9249/

I like that this thread was bumped and I found a couple posts by me that I forgot about and yet completely agree with

I feel like SOLDNER procedurally generated wilderness if you left the map bounds? I seem to remember renting that for PC, (yeah, go figure) and flying in a helicopter for like an hour and a half over just random forest, stopping every so often to shoot down some trees. I think I did that until I crashed my chopper and my objective was like 200km away.

I mean, it's either that or the Fallout 3 version where you "can't progress beyond this point" for some vaguely logical reason. The island format makes the game feel more whole and complete, while the "endless horizon" kinda thing makes it seem like "oh man, I want to go there." I guess they're both viable solutions. You can also go the Starbound route and just circle the planet around so you wind up back where you started if you go too far, but obviously that isn't going to work for a game like GTA that takes place in a specific region of the world. And, hey, if you wanna get technical: every landmass is an island.

If you went out of bounds too long in the first Bad Company game you got hit by a mortar strike.

And if you did it in text, instead of isometric 2D, you could have it span a dozen full spherical worlds. My point was clearly (or so I thought) that we will not see full real-world-sized spherical planets with modern graphical fidelity and depth. For most of the same reason that even most of the places in GTA V can't be entered. The power simply isn't there.

you need some sort of boundaries.

They should just do it like Battlefield. Once you get out of the zone you have a few seconds to go back, else you die. They can probably weave that into the story somehow.

GTA V is last generation and even so its not the hardware that limits that game to one city. Sure you cant load in the whole world into 512Mb RAM but that would just be crazy. The consoles only ever have to load in what you can see at any given time and seamless streaming of content has been done several generations back. In truth a game spanning the whole world would be no more resource demanding than GTA V but it would take the developer an lifetime to create content to fill up that world with hence it wotn happen... ever.

Buy a new GPS and you will see the whole world recreated in full 3D, its not that hard ;P

@tobbrobb: Good theory. I think that's it.